You did a good job with the cutie marks. I especially like Dumbledore's. Oh by the way, if you're going to put Ron & Hermione's pets in the picture at some point, might I suggest Pigwidgeon for Ron as opposed to Scabbers. Pig's probably a better pet anyway.

One thought I had, though... I really like that you made them all unicorns, since unicorns are magical and such. But I was just thinking, since Dumbledore is the headmaster of Hogwarts, could he possibly be an alicorn? I would imagine him that way, since Celestia and Luna are both the princesses of Equestria, and they're both alicorns. But, that's just my thought - it's really your drawing, so you can draw him how you want. ^^

Overall, this is a really cool piece, though! You definitely picked the perfect cutie marks for all of them! I'm favoriting this one!

Harry's cutie mark is the golden snitch im guessin he got it for being a seeker and for catching it? Rons cutie mark is a knight from the game of chess i think he got it for riskin his life in wizards chess and for being a great wizards chess player? Hermiones cutie mark is a book from being very studious and smart? Lunas cutie mark is a crescent moon with a bunny because ehr patronus is a bunny and her name is luna? Dumbledores cutie mark is stars and crescent moons why i am not sure Dracos cutie mark is shield with a dragon im guessin because his name is draco and hes sort of is the protector of slytherin idk XD